| Sažetak | U uvodnom djelu rada dan je pregled metoda za mjerenje tlaka okoline. Opisani su mjerni
instrumenti i njihov princip rada. Nadalje, rad se bavi pregledom metoda za ispitivanje i
umjeravanje barometara. U sklopu toga opisane su metode, tehnički i metrologijski zahtjevi
prema mjerilima tlaka okoline i opisan postupak umjeravanja prema odabranoj metodi.
Za potrebe umjeravanja instrumenta za mjerenje tlaka potrebno je projektirati etalonski sustav
u mjernom području od 800 hPa do 1200 hPa. Umjeravanja su provedena prema smjernicama
OIML-a uz pomoć barokomore. Stoga je u nastavku rada opisan etalonski mjerni sustav s
barokomorom. Elementi mjernog sustava nalaze se u Laboratoriju za procesna mjerenja.
Etalonski mjerni sustav s barokomorom sastoji se od barokomore kao osnovnog elementa,
vakuumsko tlačne pumpe, umjeravanih barometara, etalonskog barometra i uređaja za mjerenje
uvjeta okoline. Opisani su svi elementi takvoga sustava zajedno s njihovim tehničkim
podacima. Umjeravanje je izvedeno za barometar Testo 176P1 s mjernim rasponom od 600 do
1100 mbar, barometar proizvođača Lufft s mjernim rasponom od 860-1100 mbar i barometar
proizvođača Ruska s mjernim rasponom od 0 do 2600 mbar . Kao etalonsko mjerilo korišten je
barometar Vaisala PTB220 koji ima mjerni raspon od 500 do 1100 mbar. Mjerenja su
napravljena u mjernom području od 876 do 1040 mbar. Rezultati su prikazani u tablicama.
Etalonski barometar umjeren je uz pomoć tlačne vage, stoga je u radu opisan princip rada tlačne
vage, te postupak umjeravanja etalona s tlačnom vagom prema DKD-R 6-1.
Na kraju je opisan postupak za izračun mjerne nesigurnosti. Mjerna nesigurnost zatim je
izračunata za sva tri barometra. |
| Sažetak (engleski) | The introductory part of the paper provides an overview of methods for measuring ambient
pressure. Measuring instruments and their working principles are described. Furthermore, the
paper reviews methods for testing and calibrating barometers. As part of this, the methods,
technical, and metrological requirements for ambient pressure measuring instruments are
described, along with the calibration process according to the selected method.
For the purpose of calibrating a pressure measuring instrument, it is necessary to design a
reference system in the measurement range from 800 hPa to 1200 hPa. The calibration were
carried out according to OIML guidelines using a pressure chamber.The elements of the
measuring system are located in the Laboratory for Process Measurements. The reference
measuring system with a barochamber consists of the barochamber as the main element, a
vacuum pressure pump, the barometers to be calibrated, a reference barometer, and a device for
measuring environmental conditions. All elements of such a system are described together with
their technical specifications. Calibration was carried out for the Testo 176P1 barometer with a
measuring range of 600 to 1100 mbar, the Lufft barometer with a measuring range of 860-1100
mbar, and the Ruska barometer with a measuring range of 0 to 2600 mbar. The Vaisala PTB220
barometer, with a measuring range of 500 to 1100 mbar, was used as the reference standard.
Measurements were made in the range from 876 to 1040 mbar. The results are presented in
tables. The reference barometer was calibrated using a pressure balance, therefore the working
principle of the pressure balance is described in the paper, as well as the procedure for
calibrating the reference with the pressure balance according to DKD-R 6-1.
At the end, the procedure for calculating measurement uncertainty is described. The
measurement uncertainty was then calculated for all three barometers. |
